"This was in 1994 and Damien was just beginning to be a 'bit known'. We saw some publicity about a work of his, a whole lot of fish titled 'Isolated Elements Swimming in the Same Direction', and we joked that it would be nice to get something like that for the shop.

"Two weeks later our fish in formaldehyde arrived. At the time I remember thinking that must be at least £5,000 there.

"We never insured it even as Damien became more and more famous. We couldn't have afforded the insurance.

"Besides, we knew that if it was stolen Damien would give us another one. He's that kind of guy.

Damien Hirst's friend Darren Walker in the fish and chip shop

"At the time our fish was the only Damien Hirst work on public display north of the Thames."

A regional television programme was produced in 1995 in which Damien's mother, Mary Hirst, was interviewed in the shop.

The year after the gift was made Damien Hirst won the Turner Prize.

Darren Walker, who now works as an electrician, remains good friends with Bradley Hirst and lives close to his and Damien's sister. The chippie closed in 2002.

Simon Mitchell, Bonhams regional director in Leeds, said: "When the work came in to be valued we were blown away.

"It's not something you expect to emerge from a fish and chip shop.

"The inevitable question was: Is this a cod-Hirst? But of course the provenance is personal and impeccable. It's an amazing story about artistic generosity."